1. Field of the Invention
The present invention generally relates to data processing methods and apparatuses and, more particularly, to a data processing method and a data processing apparatus that allow noise contained in data to be effectively eliminated.
2. Description of the Related Art
Normally, transmitted or read data, such as image data or sound data,,contains time-varying noise. Conventionally, for eliminating noise contained in data, the whole input data may be averaged (hereinafter sometimes referred to as xe2x80x9coverall averagexe2x80x9d), or local input data may be averaged, which is referred to as xe2x80x9cmoving averagexe2x80x9d.
However, the above-described conventional techniques of eliminating noise present the following problems.
The technique of calculating the overall average is effective if the degree of noise contained in the data, i.e., the signal-to-noise (S/N) ratio, is constant. However, when the S/N ratio varies, data having a poor S/N ratio adversely influences data having a good S/N ratio, thereby making it difficult to effectively remove noise.
According to the technique of calculating moving averages, the average of data which is temporally close to input data is obtained, and thus, the processing result is susceptible to variations in the S/N ratio. That is, with input data having a high S/N ratio, the processing result also has a high S/N ratio. With input data having a low S/N ratio, the processing result also has a low S/N ratio.
Accordingly, it is an object of the present invention to solve the above-described problems.
In order to achieve the above object, according to one aspect of the present invention, there is provided a data processing apparatus for processing input data and for outputting the processed data as output data. The data processing apparatus includes an input-reliability calculator for calculating an input reliability indicating the reliability of the input data. An output-reliability calculator calculates an output reliability indicating the reliability of the output data. A correction-value calculator calculates a correction value for correcting the input reliability. A data processing unit processes the input data based on the input reliability corrected with the corrected value and based on the output reliability and outputs the output data.
According to another aspect of the present invention, there is provided a data processing method for processing input data and for outputting the processed data as output data. The data processing method includes: an input-reliability calculating step of calculating an input reliability indicating the reliability of the input data; an output-reliability calculating step of calculating an output reliability indicating the reliability of the output data; a correction-value calculating step of calculating a correction value for correcting the input reliability; and a data processing step of processing the input data based on the input reliability corrected with the corrected value and based on the output reliability, and of outputting the output data.